Behaviors of Herring and Black-Backed Gulls

Submitted by ddoyleperkin on Wed, 02/06/2019 - 15:24

Herring gulls and Black-backed gulls are two separate species of seagull that live side by side, exhibiting a wide variety of identical behaviors that allow them to communicate during significant times in their lives. These gulls breed in close quarters on coastal islands in the North Atlantic. Because of the proximity to one another, these seagulls have had to develop intricate ways of communicating with one another in order to successfully court mates, breed, nurture young, and survive. It is important to understand that animals send signals with the understanding that they will receive a response. There are three main categories of gull signaling behaviors: territoriality/aggression, parental care, and courtship. When it is a question of territoriality, gulls will always prefer to signal before engaging in aggression. One such signal is known as upright posture, which is an extension of the gull’s back and the slight spread of its wings. Upright posture is a threat display used by gulls to maintain or negotiate territory in their close-knit colonies. This display is used most often right after chicks hatch, in an effort to solidify their territory to protect their young. However, before chicks can hatch, gulls must court mates. To begin courtship, females will fly around the colony and assess the fitness of males from the air. When they find a suitable male, they will land in his territory and immediately assume one very important behavior: begging. The begging behavior is learned as a chick to ask their parents for food, but females use it during courtship to gain the trust of the unfamiliar male. This behavior is characterized by an outstretching of the neck upwards, directly into the face of the male. During this time, the female is literally asking the male for food. If the male complies and gives the female food, their pairing begins. Once gulls are paired, they establish their territory, establish a nest, and begin copulation. Copulation begins by using the same behavior that the chicks and the female once used; the begging behavior. The female gull will exhibit this begging behavior until the male agrees to copulate. The male will then stand on the back of the female and begin mating. The mating ritual is an interesting one because the male gull will use a behavior only seen during this time. Once mating has begun, the male will elicit what is known as a mating call; a unique sound that can only be heard during the mating season. The upright posture, begging, and mating call are among many important behaviors that these gulls must use to communicate, care for their young, and stay alive.

CHS PP3

Submitted by angelinamart on Wed, 02/06/2019 - 15:08

Chediak-Higashi Syndrome is a rare genetic disorder caused from a mutation in the chromosome. Patients affected with this disorder have barely no immune system due to the defect in the neutrophil, a type of white blood cell responsible to consume bacteria through phagocytosis. The whole immune system including lysosome, an organelle in the cell, and the neutrophil is incapable to dissolve the consumed bacteria, so as a result, patients have a higher rate of susceptibility to infections. Another distinguishable symptom is a physical characteristic of albinism. Patients lack not only a sufficient immune system, but also pigmentation. They have fair skin, close to creamy white, and silver streaked light hair. Since they do not have enough pigmentation, they must take extra care to be exposed under UV light. If patients with Chediak Higashi Syndrome are diagnosed early and receive proper treatment, they can live an ordinary life. However, if the treatment fails, the patient will face a stage called the acceleration phase where the disorder becomes lethal within 30 months.

Hormone Receptors: The Mediators of Hormone Action

Submitted by ddoyleperkin on Wed, 02/06/2019 - 15:03

Hormones are molecular messengers that carry out their action via hormone receptors. Hormone receptors are proteins that receive hormones secreted from various glands throughout the endocrine system. These receptors are connected to one or more effector networks that allow them to mediate the action of the hormone received. If a hormone receptor is present in a certain tissue, it outlines the target cells of a specific hormone as well as allowing for a mechanism by which the hormone can act. These receptors are known to elicit widespread effects on the human body through the use of something called “second messengers”. A second messenger relays information from the receptor to different effector systems associated with that receptor, for example, the arrival of a hormone. A very important second messenger in the endocrine system is cyclic adenosine monophosphate or cAMP. This molecule allows the endocrine system to mediate the effects of many different hormones in many different tissues. Hormone receptors are the link between the desired effect of a hormone signal and the actual effect of hormone action.

Neurons

Submitted by tokiokobayas on Wed, 02/06/2019 - 15:00

     The axon hillock of a neuron is dense with sodium voltage-gated channels, which acts as a spike-initiation zone. Once the charge is increased significantly, an action potential propagates across the neuron in an all-or-nothing action. This means that once the signal is going to go through, nothing can stop it.
    Neurons have myelin sheaths along their axons which facilitate current flow. These are found in Schwann cells in the PNS, oligodendroglia in the CNS, and help with saltatory conduction. The space in between each myelin sheath is called a Nodes of Ranvier. When a neuron is sending an action potential, the signal jumps across nodes of ranvier, to allow faster propagation of the signal. If the insulation is lost, the conduction of velocity slows. This can be seen in multiple sclerosis, which is an autoimmune degeneration of myelin sheaths.

Week3 Draft4

Submitted by mqpham on Wed, 02/06/2019 - 14:16

Different factors affect the production of phagocytes in tetrahymena species.This includes stimulations from the environment that causes the organism to produce vacuoles that are used to injest microbes. Experiments can also stimulate or hinder production of vacuoles in tetrahymena. For example, serotonin and calcium can stimulate production of vacuoles. The production of vacuoles is concentration dependent of these stimulants. However production may be inhibited by other stimulants such as high temperatures as well as taxol.

Ergot Theory

Submitted by cynthiaguzma on Wed, 02/06/2019 - 14:07

The ergot theory, which is presented in the video “The Witches Curse,” suggests that ergot played a role during the Salem Witch Trials. An event that led to the prosecution and deaths of multiple people who were accused of being witches. Linnda Caporeal claims that ergot, which is a fungus that grows on grains, led to the bizarre behavior which was exhibited in those who were said to be bewitched. Ergot releases a toxin that leads to the disease, ergotism, and has multiple types of symptoms that consist of hallucinations, gangrene limbs, and strange behavior. This disease not only affects humans but can affect animals as well. Caporeal pointed out various similarities between the disease and the bewitchment victims that linked ergot to the trials. This theory provides sufficient evidence in order to make it a plausible explanation for what had happened during the year of 1692.

 

Prion

Submitted by cynthiaguzma on Wed, 02/06/2019 - 14:04

Prion diseases can affect humans as well as animals and can be transferred to humans by the consumption of meat infected with the disease. Prion diseases are a group of progressive neurodegenerative disorders. A commonly known one is mad cow disease. These diseases are caused by a misfolded protein called PrP.  The normal function of this protein is not fully understood. The prion form of this protein is called PrPsc, the normal form of it is called PrPc. Many different mammals can be affected by these diseases since the prion protein is very similar across multiple different mammals. The problem with this disease that can be found in meat is that the prions cannot be destroyed using the usual methods, boiling, autoclaving, and radiation will not get rid of the prions. This disease can lead to holes in the brain and eventually to death. There are various different symptoms of this including, seizures, slurred speech, and memory loss.

 

PanINs

Submitted by sditelberg on Wed, 02/06/2019 - 11:30

Pancreatic intraepithelial neoplasias (PanINs) are the precursor lesions for pancreatic adenocarcinomas, the exocrine form of pancreatic cancer. There are multiple types of PanINs, each building up to pancreatic adenocarcinomas. The lowest grade, called PanIN-1, frequently has mutations in the KRAS oncogene. In PanIN-2s, p16/CDKN2A gene mutations start to appear. PanIN-3s, the highest grade of these precursor lesions, accumulate SMAD4 and TP53 mutations. At times, these SMAD4 and TP53 mutations don't appear until the adenocarcinoma has already become invasive. The researchers plan to examine all of these mutations and come up with novel targeted therapies for each stage of PanIN in an effort to halt the progression of pancreatic adenocarcinoma. Once past the PanIN stage, surgery remains the only form of treatment that has a slightly longer survival rate.

From Larvae to Fly

Submitted by alanhu on Wed, 02/06/2019 - 11:20

My larvae that was given to me by choice at the end of the first class had turned into a cocoon on the 26th of January. On the 6th of February (11 days in a cocooned state) a fly emerged from the cocoon. The fly has four legs and two manible looking like structures. There are two transparent wings on the dorsal side of the fly. The eyes are orange in color and large while the body was black and round. The body of the fly is fuzzy. The fly clings to the side of the container and shifts around once in a while. The challenging part at this point is to find a way to open the container to give the fly some food. There is a risk of the fly getting out of the container and into the open world. 

DNA Extraction and Quantification Results

Submitted by ewinter on Wed, 02/06/2019 - 11:09

The average concentration of the two trials of RNase treated samples is 336.75 ng/uL, the average 260/280 ratio is 1.60, and the average 260/230 ratio is 0.60 [Fig. 1].  The average concentration of the two trials without RNase treatment is 292.05 ng/uL, the average 260/280 ratio is 2.05, and the average 260/230 ratio is 1.57 [Fig. 2].  The average concentration of all four trials is 314.4 ng/uL.  This means in the original 50 uL of solution, there were 15,720 ng of DNA. 

Looking at Figure 3, lane 1 contains a visualized DNA ladder while lane 2 does not.  Lanes 3 and 4, the RNase treated samples, show two bright bands of slightly over 10,000 base pairs in length and no difference in intensity between the diluted and undiluted samples.  Lanes 5 and 6, the untreated samples, show these same two bands, although in the ½ dilution this band is noticeably fainter.  In lanes 5 and 6, there are large discolorations spanning the range of 0 to 500 base pairs, and in the diluted sample, it is noticeably fainter.

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